The present invention relates to high speed equipment for filling bottles or other containers with liquids (especially carbonated liquids). More particularly it relates to actuator assemblies that control valve positioning in such equipment.
It is well known to fill bottles and other containers with liquids using automated equipment. For example, Krones AG commercializes a line of “Mecafill VKP” automated filling machines.
Fillers of this type progressively fill bottles at high speed as a line of the bottles are caused to move to, around and then away from the machine. Typically, there is an axially movable linkage structure and filling chamber over the top of each bottle as it is being filled. Controlled axial valve movement in each such filling chamber facilitates removal of air in the bottle and filling of the bottle with a beverage (or other liquid) and often carbon dioxide.
This is typically achieved by having the valving structure mechanically linked to an actuator, which in turn is pivoted by a cam follower arm. See e.g. the valve actuator 78 in U.S. Pat. No. 5,960,838.
One problem that has arisen in using such equipment is that various models of this type of equipment have a tendency to develop leakage of carbon dioxide over time. For example, leakage can occur along a passageway between a follower arm and a linkage fork shaft due to wear.
Another source of linkage is that many machines of this type use springs to hold various parts together or against each other. Those springs can lose their biasing force over time, and thereby lead to leakage.
Such leakage wastes carbon dioxide (and thus somewhat increased cost). Moreover, there is increasing regulatory interest in avoiding unnecessary carbon dioxide emissions (due to climate change concerns).
In various contexts magnetic couplings have been used as one means of transferring motion from one assembly part to another. See e.g. U.S. patent application publication 2009/0071566, and U.S. Pat. Nos. 4,163,464, 4,671,486, 5,927,564, and 6,179,016.
In any event a need still exists for improved valve actuators for use with high speed automatic bottle filling equipment.